Battery life draining fast, but stops after long phone sleep.

I have an android phone which have a 2000mAH battery, I used it mostly for games, the first time I used the phone it's okay on its battery life, but after it drains too fast, but the battery meter stops once I used it after long phone sleep, is there anything to fix this?

As much battery gets used as you use. The only way to not use battery is to take the battery out of the phone (which isn't the answer you want). A repair shop may find a problem in the phone that's draining the battery, but it's not a do-it-yourself project.